The present invention relates generally to aircraft brakes, and in particular to aircraft brake assemblies that are convertible from a first type of heat sink to a second type of heat sink.
Aircraft brakes having a steel heat sink have been utilized for many years. Such brake assemblies commonly include a plurality of steel rotors, a plurality of stators with friction material pads attached thereto, a plurality of friction material pads attached by rivets to the backing plate of a torque tube, and piston bushing assemblies. Steel heat sink aircraft brake assemblies have proven to be economical, reliable, and desirable for aircraft that fly relatively short hauls. Carbon-carbon composite heat sink aircraft brake assemblies have become more prevalent as the size of commercial aircraft has increased. Typically, commercial aircraft flying long distances or long hauls may increase revenue and/or reduce operating costs by utilizing the significant weight benefits offered by a carbon-carbon composite heat sink as compared to a steel heat sink. However, if an aircraft with carbon-carbon composite heat sinks is scheduled to fly a short haul, the use of such heat sinks may not be cost effective. Therefore, given a sufficiently sized wheel cavity it is highly desirable to provide an aircraft brake assembly designed as original equipment to be easily converted from (and compatible with) a first type of heat sink to a second type of heat sink. It is highly desirable that a carbon-carbon composite heat sink of an aircraft brake assembly be easily converted to a steel heat sink, and vice versa. This would provide significant advantages over converting or retrofitting an existing brake assembly from a carbon-carbon composite heat sink to a steel heat sink which could result in a heavier steel aircraft brake assembly than a brake assembly designed originally to be only a steel aircraft brake assembly. Converting an existing carbon-carbon composite heat sink aircraft brake assembly to one having a steel heat sink can result in a brake assembly having an overly large torque tube and/or pistons that result in unnecessary weight. Too much weight can result in difficulties with retracting the landing gear. With the present invention, an airline would be able to order a group or fleet of aircraft suitable for both long and short hauls, with the long haul aircraft utilizing carbon-carbon composite heat sink aircraft brake assemblies while the short haul aircraft utilize the more economical steel heat sink aircraft brake assemblies. Should changes in scheduling occur or certain planes be needed for longer or shorter hauls, the particular type of heat sink utilized in the brake assemblies can be converted easily to a different type of heat sink.